Figure 3.

Characterization of fourth- and third-order veins (veins containing ≤14 sieve elements and phloem area/vein area ≥0.5) from leaves of Italian, Col-0, and Swedish ecotypes of A. thaliana grown under different controlled temperature (°C daytime leaf temperature) and light (μmol photons m⁻² s⁻¹) conditions. (A) Sieve element number per minor loading vein. (B) Cross-sectional area of sieve elements per minor loading vein. (C) Companion and phloem parenchyma cell (CC + PC) number per minor loading vein. (D) Cross-sectional area of CCs + PCs per minor loading vein. Mean ± standard error of the mean (n = 4 plants). Statistically significant differences indicated with lower case letters (P < 0.05), i.e., means sharing a common letter are not statistically different from one another.